I'm on the fence, in terms of the issues (as you'll no doubt have seen, from my posts around 12 hours ago)

At the beginning of the year, I was slightly keener on the Calyx-M, but then they persisted with that stupid, stupid, stupid magnetic volume slider, and stealthily increased the weight from 160g to 230g, which is almost as heavy as an HM-901/DX100.

I want to see the DX90 overcome the teething issues, and then I'll more than likely go ahead and buy one. I can't think of anything else on the market that matches the SQ at $419 and a mere 140 grams.

All good points but with iBasso, considering my experience with my DX50, it's always been a difficult thing to get right, it took quite a few months to move to 1.2.8 and it is still not fully functional, so my feelings is that you'll never reach this so called status of done. I understand your quest for less expensive and SQ improvement but with all ventures, something's gotta give (there is nothing like a free lunch, sooner or later you'll pay, spending lots of time fiddling around with the player is money lost doing something else cause time is money lol). The pool of resources at iBasso is limited and you'll never reach the level of a Sony and Apple on the front. With the DX50 and DX90 unfortunately it will never be done so the best time to join is now and participate in the journey of improving it months at a time.

Nope. Planning on using the phase-flipped noise reduction and extra drive to clean up the sound and widen soundstage, etc. Look up Tyll's posts on balanced headphone amping.

Kojaku

Yeah good luck, I don't hear audible noise from what the current built-in amp is pumping that is worth taking the extra mile. It may turn out cleaner than stock alright and show up on measurements but I still doubt there would be an audible difference.

Yes but the shared grounds at the TRS jacks break the complete balanced output, so we get none of the benefits. Honestly dual-DAC without balanced output it a bit odd...they may as well have built a really good 1-DAC implementation and added another SD slot or something.

Kojaku

Sure, I didn't mean to imply that 'nearly balanced' equates to 'why bother' - I meant 'nearly balanced' as in 'wouldn't require much electronics modification to accomplish a true balanced HO'.

On the other hand, RWAK120, iirc, compromises by skipping the amp stage 'entirely' to offer a balanced LO from the DAC chips, with no HO (either balanced or single-ended) available.

In order to retail a mod, it needs to convince people that it's worth the cost of the mod, not just in terms of functionality, but also in terms of -perceived skill of execution. If the DX90 is so near to offering a balanced HO, then it may be relatively easy for DIY-ers to accomplish the task.

Add that factor to my previous one about the $419 pricetag of the DAP, and a luxury-priced mod for the DX90 looks... well... less likely to stand up to economic scrutiny than one on a $1300 DAP.

Well that's the point. This is to get support for an R&D unit to be developed so that he can hone in on the perfect mod set. I assume it'd at least involve looking at output impedances (maybe changing them like in the RWAK100) and of course introducing balanced output, which many are interested in.

Kojaku

Well this is the same old software/hardware engineering problem, unless I see specs how do you expect me to pay for something that does not even exist and even not knowing how much? What I would suggest is for Vinnie to look at your unit, let him see what it would need to make it balanced and then recruit 10 people who's willing to pay for it. Your recruiting is just plainly started at the wrong end, no common person will go ahead with a carte blanche, I don't know about the others but I need numbers, how much what and when. Can you get that?

Yeah good luck, I don't hear audible noise from what the current built-in amp is pumping that is worth taking the extra mile. It may turn out cleaner than stock alright and show up on measurements but I still doubt there would be an audible difference.

There is an audible difference but for someone not believing in hi-res there is no point saying it does, I have a balanced unit and can tell you the sound out of it is cleaner, stronger and feels extended however you'll need to balance wire your phones cause it now becomes a necessity so quite a bit of costs involved however for someone who wants to squeeze ounces of SQ they may find it worth it.

Well this is the same old software/hardware engineering problem, unless I see specs how do you expect me to pay for something that does not even exist and even not knowing how much? What I would suggest is for Vinnie to look at your unit, let him see what it would need to make it balanced and then recruit 10 people who's willing to pay for it. Your recruiting is just plainly started at the wrong end, no common person will go ahead with a carte blanche, I don't know about the others but I need numbers, how much what and when. Can you get that?

I suppose I can try. I'll see what he says. I honestly don't know if I'll have enough numbers to convince him to look at it, the way things are going, though. We may just have to suck it up and wait for a Chinese modder to figure it out.

I think they got the update pretty right. I like the extra life in the sound of the FW and prefer slow roll filter. I'm sure they'll tweak it more but this has more soul. If I want to take a little energy away, I can choose a lower gain setting which seems to damp things a hair. Navigating is faster, smoother and has better touch sensitivity. Hope the next one adds a phase inversion option.

I'm wondering if it would be possible for iBasso to implement crossfeed in the DX90, I know the DX50 can do it with rockbox. It might take some extra power but that if that means that long listening session become more comfortable I'd love that.

I think they got the update pretty right. I like the extra life in the sound of the FW and prefer slow roll filter. I'm sure they'll tweak it more but this has more soul. If I want to take a little energy away, I can choose a lower gain setting which seems to damp things a hair. Navigating is faster, smoother and has better touch sensitivity. Hope the next one adds a phase inversion option.

I totally agree with this. The only small wish I have now is if the sampling rate and bit depth display could be replaced by a track X of Y display. Everything else I use works perfectly now and the sound out to my SR71-B is great.

I suppose I can try. I'll see what he says. I honestly don't know if I'll have enough numbers to convince him to look at it, the way things are going, though. We may just have to suck it up and wait for a Chinese modder to figure it out.

Kojaku

Thanks, just tell him what I said and see if he can commit to that, you might be able to get more than ten if he has a workable solution that would also be economical (might be wishful thinking here but worth asking for it), otherwise I would rather want to go for a design that is already baked in, at the end it will be cheaper and for sure will work because it will be implemented with the function spec'ed out. No hard feelings though and thanks again for getting involved.

I think they got the update pretty right. I like the extra life in the sound of the FW and prefer slow roll filter. I'm sure they'll tweak it more but this has more soul. If I want to take a little energy away, I can choose a lower gain setting which seems to damp things a hair. Navigating is faster, smoother and has better touch sensitivity. Hope the next one adds a phase inversion option.

The slow roll filter doesn't sound completely accurate to me, but it does have a musicality about it. The sharp roll filter is more accurate but is even more lifeless than the original firmware. I like the balance of the original firmware, to me its sounds like its in between sharp and slow roll off. That aside, I find the micro detail and layering better on original personally.

There is an audible difference but for someone not believing in hi-res there is no point saying it does, I have a balanced unit and can tell you the sound out of it is cleaner, stronger and feels extended however you'll need to balance wire your phones cause it now becomes a necessity so quite a bit of costs involved however for someone who wants to squeeze ounces of SQ they may find it worth it.

I too have a balanced unit but it doesn't sound cleaner or stronger either way if the signal is already clean and amp is powerful enough for the phone used.

My point was in the case of DX90, which is already clean any noise you will further reduce by going balance doesn't merit the cost and risk imo.

The slow roll filter doesn't sound completely accurate to me, but it does have a musicality about it. The sharp roll filter is more accurate but is even more lifeless than the original firmware. I like the balance of the original firmware, to me its sounds like its in between sharp and slow roll off. That aside, I find the micro detail and layering better on original personally.

Slow roll sounds more correct to me. Whatever it is that doesn't agree with you will have to do with your preference for the sound of the old FW and likely not the filter. They may have been using slow roll in that one as well. No way to know unless they say. I'm always more concerned with rhythm and message when it comes to music. I prefer this one as the old one would sometimes not move me as well. I fully respect your preference. It's just different than mine. It's often the case that a less dynamic sound is less masking of low level info but that doesn't mean it's more correct. In this case I think both sound VG so it's not a biggie.

The slow roll filter doesn't sound completely accurate to me, but it does have a musicality about it. The sharp roll filter is more accurate but is even more lifeless than the original firmware. I like the balance of the original firmware, to me its sounds like its in between sharp and slow roll off. That aside, I find the micro detail and layering better on original personally.

Actually I like how the new firmware sound with Roxanne. I can still hear the same amount of details but could not tell how different it is with the original FW. Can't rollback at the moment as DX90 does not recognize the original FW image file and the RKBatchtool iBasso supplied only works on Windows.